The so-called Philips lamp is a kind of indoor fluorescent lamp which has greatly improved conventional fluorescent lamps such as mercury vapor lamps and the like. The light of the Philips lamp is more gentle, and harmful elements such as ultra-violet rays are diminished.
Because the duration of the Philips lamp is longer than that of both conventional light bulbs and fluorescent lamps, and its light is more gentle and it produces less heat, the Philips lamp is becoming more popular. However, whatever shape it has, the current Philips lamp is not as convenient as conventional light bulbs. For instance, light bulbs or some fluorescent lamps are suitable for use with a DC or AC power source. By disposing a transformer and a rectifier in the lamp base and putting a battery in place, conventional lamps using light bulbs or fluorescent lamps may be used with a DC or AC source. Therefore, the emergency lights for indicating the direction of exit provided at the emergency exits of most buildings are mainly light bulbs. Normally, the battery in such emergency lights is charged by an AC power source. When AC is cut in a power failure, the DC source of the electricity storing means will automatically start the bulb.
But up to now, there is not any Philips lamp that can use DC/AC power sources to automatically switch to DC power source when AC power fails in order that the lamp can work for a few hours. Furthermore, the construction of the conventional Philips lamp does not allow the lamp base to be detached from the lamp pole so that the lamp base itself becomes a portable Philips lamp. It is therefore necessary to improve the conventional Philips lamp so that it is more convenient for carrying and has wider applications.